infantile

Definitions

Relating to or occurring among infants or in infancy.

Childish; displaying a lack of maturity or adult behavior.

Examples

His infantile behavior during the meeting made it difficult for his colleagues to take him seriously.

The critic dismissed the film as an infantile comedy that lacked any real depth or substance.

Synonyms

childish immature juvenile puerile babyish infant childlike

Antonyms

mature adult grown-up sophisticated developed experienced responsible